FvwmCommand (FvwmCommandS)

Have tried to find a help forum for Fvwm* stuff, but can't find any.
My be just tipping me of one is enough.

The problem:
Have made an application using FvwmCommand that works fine when
running under /root (super user, SU). However, when running under a "normal"
user it fails by the FvwmCommand fifos.

[Thomas]
I use nothing but fvwm
I love it. It would be
useful to know which version of fvwm you're running.

My understanding:
The FvwmCommandS sets up 2 fifos (C,M) in /var/tmp and always get
the permission prw-------. Those fifos doesn't seem to be accessible
from none SU.

[Thomas]
Yeah -- I checked the Changelog file for fvwm version >=2.3.0, and
there was a bug within the FvwmCommand
module. However, as of version 2.3.6, it was fixed.
I'd upgrade to the latest stable release.

When trying not SU, always get the report:

No such file or directory FvwmCommand error in opening message fifo:
Permission denied.

May be this is deliberately from some security point of view, but on the
other hand FvwmCommand is "x for all" in my default installation.

Best regards

[Thomas]
As Heather goes on to explain, it is most likely a
umask problem.

I'm a fvwm fan myself, but I've not used the FvwmCommand module.
Generally I just put things on the menus as Exec calls.

However, it sounds like a umask problem; and possibly a permissions
problem in the filesystem. /var/tmp, rather like /tmp, should be
permissions 1777 (sticky-bit, everybody can see and write and stat
things in the directory). The permissions your file got would be
sufficient to defend it from other accounts reading it, but should
allow the creating account to work with it. Also note that it's not
executable; you weren't trying to create a script and then run it,
were you?
-- Heather

[Thomas]
But that's what FvwmCommand can do heather! It's
supposed to do that

Is it also supposed to refuse to do it if the result is
not marked executable?

For doing, um, dynamic things I like to have a tmp under
my homedir, which belongs only to me (mode 0700) so I
can do strange things but I don't subject myself to
possible nosy other users. Mind you, I don't usually
have other users to worry about, but what the heck; I plan
some things here that may get put in production elsewhere.
-- Heather

Thanks for your answers and appologies for my late
response. Have been away we no net capabilities.

I agree that it looks like a permission problem as is
actually reported. There should be no problem with
the /var/tmp directory permissions. They are both
"rwx" (7) for all.

The problem seems to be related
to FvwmCommandS that sets up (I guess) the two Fifos
and also sets the permission to prw-------. By the way,
what does "P" stand for.

p stands for named pipe. Stdout (standard out) of one
process may be set to feed into a pipe, and the program
attached to pick up stdin (standard input) from that pipe
can use that to do whatever it needs to do next.

Both the programs should have the permission to reach the pipe
that has been created; the umask of the fvwmcommand process
is probably restricted to prevent nasty side effects.
-- Heather

Have tried after FvwmCommandS
is spawned to (as SU) change the fifo permissions by all
sorts of combinations with no luck. Typically I can get
to prwSrwSrw-. In chmod I used "s" but comes out as "S".

That's because it had no execute permission; since the "Suid"
shares a space with the "eXecute" bit, a way was needed to show
that both are set, or only one of them,

execute but not suid:
for owner and group, the first two triplets: rwx

execute AND suid:
for owner and group: rws

not execute, but suid. This doesn't make sense for most purposes:
for owner and group: rwS

execute but not sticky:
for "other", the third triplet: rwx

execute and sticky:
for other: rwt

not execute, but sticky. again it's rare for this to be reasonable:
for other: rwT

Now, since the suid, exec, and sticky bits don't affect the read or
write, those "rw" could really be any of "r-" "-w" "--" or "rw".
-- Heather

My version of FvwmCommand is 2.4.7. I do not know what,
or how to find out the version of FvwmCommandS.

I do not know that either. Perhaps Thomas Adams or one of the other
Answer Gang members can help further.
-- Heather

Thanks a lot for the information on permissions. Some of them were new
to me.

Honestly, I have to tell that I have rewritten the application in order not to
use FvwmCommand, but it is still interesting to know where the problem
sits. It may be useful in the future.

Just for testing I have done the following (may be someone can do the same ?).

I have set the permissions as (a lot shouldn't be needed, but just for test):
FvwmCommand: -rwsr-sr-x
/var: drwsrwsrwx
/var/tmp: drwsrwsrwt

FvwmCommandS is spawned by fvwm95 (using that).
When spawned I changed (as root) the two fifos permissions
to: prwsrwsrwx

From an xterm I run: FvwmCommand Restart fvwm95.
Works when logged in as root but not as !root user.

Well, as having rewritten the application it is no longer of utmost importance.

The Answer Gang has been of a lot of help in the past. Thank you all.

Best regards
Hans.

During this thread I cc'd the Answer Gang back in so
the entire Gang can help you out here. Any one of us could
go underwater with complicated questions, so we do not "assign
techs" to help anybody all alone. Good thing too - nice to have
Thomas confirm what I was groping around in the dark about...

... and that's where it comes to you, dear readers. Hans solved
his problem, by avoiding it. But if anyone happens to know what
it's really up to - was it really a bug in that version, does it
really work now? If anyone else out there is using fvwmcommand
actively, drop us a line and let us know what you're doing with
it. I presume, making FVWM a little more fun

Other articles or replies about making your favorite window manager
do cool and weird things are also welcome. If we get enough maybe
it could be the month of "The Truly Cool Things We Did To Our Computers"
-- Heather

Installing Redhat on Dell X200 laptop (via 1394 CD)

Please help me install Redhat 7.3 on my Dell X200 laptop.
This machine has a firewire CD from which I am able to start the install
process.
However, the install process soon asks for the device from which to do
the install (NFS, FTP, Hard disk, etc.).

No option is given for CD.
It looks my BIOS can see the 1394 CD but Redhat cannot.
I've looked in all the obvious places for 1394 firewire drivers (Redhat,
Dell, Linux documentation and discussion sites).
Please help. NFS/FTP boot is not an option.

Thanx,
Jim Montgomery

[Heather]
For that matter, if our readers know any distro that would cleanly
install from a firewire CD, let us know. Distro vendors - look forward
to more questions like this!

The last word on "daemon"

I have read on the December Linux Gazette (mailbag) another letter about
the etimology of "daemon". Usually for this kind of things the ultimate
source of knowledge is "The Jargon File" by Eric S. Raymond, aka ESR
(aveilable at the URL http://www.tuxedo.org/~esr/jargon) .

The jargon file entry was mentioned in the starter to this thread,
which began in the October issue when someone confused about Kylix
made a wildly incorrect guess about the origin of "daemon" and was
immediately fed all sorts of tasty bits by The Answer Gang. I thought
the timing was quite excellent as it arrived perfectly for Halloween.
http://www.linuxgazette.com/issue83/tag/1.html

It has since seen replies in November's and December's mailbag
http://www.linuxgazette.com/issue84/lg_mail.htmlhttp://www.linuxgazette.com/issue85/lg_mail.html
which remove the haze of years that a glossary entry generally
summarizes out of existence, to describe current usage only. The
Jargon File doesn't always do this, but the information lost by not
being quite common enough "common knoqledge" before this began to be
set down as bits (and eventually paper) sadly does the glazing over
quite well enough.

"ultimate" is a strong word and frankly I rarely use it for anything.
Anyone who's been in this business long enough knows that to depend upon
only one source for your research isn't really "ultimate" at all, and
I'm pleased to have drawn some historians out of the woodwork with more
complete info than the Gang pulled out of our wizard hats at the end of
September.

In fact, I think the Jargon File maintainers may well like to add details
from the etymology-of-daemon thread updates to their entry. To make it
more likely, I've cc'd their maintainer list.
Hi Eric, and everybody

As of press time, I haven't seen an update to this entry in the Jargon File
as a result. No worries. It's probably because I didn't follow their
posting guidelines more closely...
-- Heather

We welcome new jargon, and corrections to or amplifications of
existing entries. You can improve your submission's chances of being
included by adding background information on user population and years
of currency. References to actual usage via URLs and/or Google
pointers are particularly welcomed.

...............

Booting multiple OS's

moral: pay attention during hardware upgrades.

Your answer gang column in issue 85 had an article
"Triple Booting" and
had 1 segment of a triple boot as Windows 98.

Recently, I decided to upgrade my P3 MB to a P4 at 2.4gz. There was a
combo of an Soyo P4vda MB and the P4 2.4gz that I couldn't resist. I did
a lot of reading and the installed the MB. I also have a Slackware and
Mandrake Linux installation.

On boot up, I got an error message from W98 that initialization of the
NDIS had failed and the system had to be rebooted. It turned out that
the only way it would boot from that point was in the safe mode.
Needless to say, that's like being on a dead end street with no place to
go. My 2 Linux installations were not accessible because the Promise
card had been removed and they were now on hda and hdb and I couldn't
get them to boot.

It seems that W95 & 98 at this speed of a P4 processor can only be
made to work by getting a fix from Bill's os. Since my Pc was dead in
the water, there was no way this could be done and the alternative was
to install WXP. My true instincts said install Linux and to hell with
windows.

Anyhow, its all said and done and WXP as far a I am concerned is a piece
of crap. I sooner setup a graphics card in Slackware Linux than deal
with what XP has to offer.

My reason for this litany of misery is to ward of some poor soul who
might have the temptation to use this combo of a P4 2.4gz or higher
processor with W95 or W98. You would think that somewhere there would be
a flag to warn us but it was only after a call to Soyo, the MB
manufacturer, that I learned of this pitfall. People tell us hard Linux
is, if I had chosen this combo to install on Linux life would have been
a bed or roses.

Thanks

I found the back issues of the Gazette included in the Debian CDs. Another
hidden gem. This alone was worth the purchase price. I enjoy the format of
multiple answers to questions (eg: the answer gang) and I am suprised that
other publications have not tried to copy the format. It kind of has the
feel of being subscribed to a news list I subscribed to 'Linux Journal' a
couple of years ago because of 'linux Gazette'.

Heather specifically wanted The Answer Gang to read like an informal
conversation, so that's how she edits it. I don't know why nobody else
has copied the style. For LJ, it may be because of tradition and space.
The Answer Gang takes up a lot of space when printed, and print magazines
have only a limited number of pages, so you'd have to drop a couple articles.
But people buy LJ for the articles. -- Mike

(curtsy) thanks for the compliment, guys. I figure, a thick enough
thread feels a little like an installfest... all these clues flying
around at high speed... bonking people occasionally, but all in good
fun.
-- Heather

As for the Debian CDs, those are handled by the Debian Project and the CD
vendors, so it's their job to promote them. We do have LG on the Linux
Journal Archive CD (store.linuxjournal.com, under "LJ Archives").
-- Mike

Re: virtual beer and feature request

Can it be possible to append the author bio to the
TWDT file. Or maybe make a TWDT for the author bio
itself for each issue.
I really enjoyed reading the bios
.

We'll think about this. One of the purposes of the
Author pages is
to have the latest contact information and bio; the
articles and TWDT
would not be changed after publication.

Pehaps I can put the entire bio page (minus the
links to previous articles,
and minus the large type in the header) at the
bottom of the TWDT article,
with a note that this information may be old and
another link to the
Author page.

Thanks for looking into my feature request about the
author's bio. What you suggested is exactly what I
wanted.